基于涡轮叶片修复的电解修型非加工面保护工艺

Non-machined Surface Protection Process of Electrochemical Machining Based on Repaired Turbine Blade

为提高民用客机涡轮叶片修复效率,对叶片修复工艺链中电解修型非加工面保护工艺进行了研究。通过建立电场的数学模型,对叶片表面电流密度分布进行数值计算,研究修型规律,并以此分析传统电解修型工艺的缺陷形成机理。提出了牺牲层工艺保护非加工面,并建立实验系统,对堆焊修复后的TC4叶片进行电解修型。结果表明:直接修型、绝缘层保护两种传统工艺将分别形成杂散腐蚀和"台阶"缺陷;采用牺牲层工艺,单组叶片修型时间60s,修型后的叶片精度较高,表面粗糙度Ra≤0.6μm,具有较好重复性,满足设计要求。

In order to improve the efficiency of turbine blade repairing,protection processes of non-machinedsurface in Electrochemical Machining(E C M)based on blade repairing were studied.M athematicalmodel of electric field was developed to obtain current density distribution on anode surface,and to study the repairing principle and consequently analyze the defects forming mechanism by conventionalelectrolytic repair process.Sacrificial layer process was proposed to protect the non-machinedsurface in this work and an experimental system was developed to shape overlay welded TC4blades.T h e results show that directly shaping process and insulated layer process produce stray dissolutionand“stair”defects respectively,while sacrificial layer process achieves acceptable machiningperformance.With shaping time of60s,the efficiency is improved;shaped blades have higher precisionand surface roughness is R&^0.6jLtm,and with higher repeatability,the design requirements canbe met.